The invention concerns a method of manufacture of a lighting device, especially a headlamp or rear light of motor vehicles, whose housing with light source is closed by a transparent cover.
With the improvement in the precision and perfection of assembly of vehicles the demands are also growing for the accuracy of attachment of the headlamp to the body of the vehicle. It is necessary that the headlamps and signal lights for motor vehicles be manufactured with less standard deviation from the nominal position and also with a uniform distribution of deviations over the entire circumference of the lamp.
A method for manufacture of a headlamp for a precise installation is known from EP1939076, whose purpose is to do away with the need for further adjustment of the position of the headlamp after assembly on the frame of the vehicle. The assembled headlamp is placed in the machining station such that the reference points of the transparent diffusing cover of the head lamp are set against control elements of the machining station whose positions correspond to the correct spatial arrangement, next a sensor determines the effective position of the first grasping means of the housing of the headlamp with respect to the position of the control elements, then the control unit of the machining station compares the determined effective position of the first retaining means with its nominal position which is needed for mating with a coupled second retaining means of the vehicle frame and finally the first retaining means is machined by removal of at least part of its excess to enable a mating with the second retaining means. The drawback of the solution according to EP1939076 is the machining of the first retaining means of the housing, which is spatially difficult, insufficiently precise, requires costly machining equipment and tooling, and produces a lot of unwanted wastes which need to be comprehensively disposed of.
There is known from DE102004005978 a method of mounting of a headlamp on a mounting support, located in the front part of a vehicle and provided with openings for precision fastening of the headlamp. The mounting support is placed on a mounting rack, whose connection points correspond to the frame of the vehicle. On the mounting support, the precise positions of the connection points for fastening of the headlamp are determined by measurement and transmitted to the computer of a program control robotic center. The headlamp is placed by its reference points on a template, the positions of the connection points on the housing of the headlamp are determined by measurement and also transmitted to the computer of the program control robotic center. In the computer of the robotic center, during the required tolerance equalization, the corrected positions of the connection points on the mounting support are calculated. At the connection points, a robot brings up thrust pads belonging to thrust elements to the mounting support and they are inserted at a depth corresponding to the corrected positions of the connection points. The method of mounting of a headlamp according to DE102004005978 is complicated and its precision is not adequate.